transaction started in ::store_lock() and not by startStatement/Transaction

[Stewart Smith]

For the following sequence:

create table t1 (a int, b int not null, c int null, d int not null);
show create table t1;
insert into t1 values (0,0, 0, 0);

when HTON_SKIP_STORE_LOCK is set for the engine and with autocommit on, we get no call to startTransaction or startStatement.

If HTON_SKIP_STORE_LOCK is *NOT* set, then (at least) innobase sets up the transaction (check_trx_exists()) in ::store_lock call in the mysql_lock_tables (for mysql_insert()).

backtrace:
#0 check_trx_exists (session=0xa21f00)
    at plugin/innobase/handler/ha_innodb.cc:1423
#1 0x00007ffff496f8b9 in ha_innobase::store_lock (this=0x1230968,
    session=0xa21f00, to=0x1231d98,
    lock_type=drizzled::TL_WRITE_CONCURRENT_INSERT)
    at plugin/innobase/handler/ha_innodb.cc:7500
#2 0x00000000004d3064 in get_lock_data (session=0xa21f00,
    table_ptr=0x1224bc8, count=1, should_lock=true,
    write_lock_used=0x7fffe4ddfab8) at drizzled/lock.cc:626
#3 0x00000000004d20e7 in drizzled::mysql_lock_tables (session=0xa21f00,
    tables=0x1224bc8, count=1, flags=4, need_reopen=0x7fffe4ddfb7f)
    at drizzled/lock.cc:189
#4 0x0000000000551e98 in drizzled::Session::lock_tables (this=0xa21f00,
    tables=0x1224818, count=1, need_reopen=0x7fffe4ddfb7f)
    at drizzled/sql_base.cc:2196
#5 0x000000000053d9e8 in drizzled::Session::openTablesLock (this=0xa21f00,
    tables=0x1224818) at drizzled/session.cc:2016
#6 0x000000000055b77d in drizzled::mysql_insert (session=0xa21f00,
    table_list=0x1224818, fields=..., values_list=..., update_fields=...,
    update_values=..., duplic=drizzled::DUP_ERROR, ignore=false)
    at drizzled/sql_insert.cc:250

interestingly enough though... we do seem to get a commit():

#0 innobase_commit_low (trx=0x1230e00)
    at plugin/innobase/handler/ha_innodb.cc:2050
#1 0x00007ffff4966e9e in InnobaseEngine::doCommit (this=0xa36010,
    session=0xa21f00, all=false) at plugin/innobase/handler/ha_innodb.cc:2175
#2 0x00000000005da7a4 in drizzled::plugin::TransactionalStorageEngine::commit
    (this=0xa36010, session=0xa21f00, normal_transaction=false)
    at ./drizzled/plugin/transactional_storage_engine.h:84
#3 0x00000000005d9499 in drizzled::TransactionServices::ha_commit_one_phase (
    this=0x9de6d8, session=0xa21f00, normal_transaction=false)
    at drizzled/transaction_services.cc:594
#4 0x00000000005d937d in drizzled::TransactionServices::ha_commit_trans (
    this=0x9de6d8, session=0xa21f00, normal_transaction=false)
    at drizzled/transaction_services.cc:564
#5 0x00000000005d989a in drizzled::TransactionServices::ha_autocommit_or_rollback (this=0x9de6d8, session=0xa21f00, error=0)
    at drizzled/transaction_services.cc:715
#6 0x000000000056b5c6 in drizzled::dispatch_command (
    command=drizzled::COM_QUERY, session=0xa21f00,
    packet=0x1226841 "insert into t1 values (0,0, 0, 0)", packet_length=33)
    at drizzled/sql_parse.cc:246

[Stewart Smith (stewart)]

Jay, I assigned this to you as you've been playing around with that code recently and may be able to resolve it a bit quicker than me... although I'm happy to take it if wanted (but will be a little while before I get to it).

[Jay Pipes (jaypipes)]

No prob, Stew. It needs to be fixed, and this is just one symptom of the asinine PSEAPI. Thanks for the bug report.

[Jay Pipes (jaypipes)]

Should be fixes in lp:~jaypipes/drizzle/bug534806.

Please merge that branch in and test if that fixes this bug as well.

Thanks!

Jay

[Stewart Smith (stewart)]

The following patch will hit the assert when running the embedded_innodb test suite

=== modified file 'plugin/embedded_innodb/embedded_innodb_engine.cc'
--- plugin/embedded_innodb/embedded_innodb_engine.cc 2010-09-27 09:04:26 +0000
+++ plugin/embedded_innodb/embedded_innodb_engine.cc 2010-09-28 05:40:05 +0000
@@ -617,20 +617,7 @@ THR_LOCK_DATA **EmbeddedInnoDBCursor::st
                                                  THR_LOCK_DATA **to,
                                                  thr_lock_type lock_type)
 {
- /* Currently, we can get a transaction start by ::store_lock
- instead of beginTransaction, startStatement.
-
- See https://bugs.launchpad.net/drizzle/+bug/535528
-
- all stemming from the transactional engine interface needing
- a severe amount of immodium.
- */
-
- if(*get_trx(session) == NULL)
- {
- static_cast<EmbeddedInnoDBEngine*>(getEngine())->
- doStartTransaction(session, START_TRANS_NO_OPTIONS);
- }
+ assert((*get_trx(session)) != NULL);

#2 0x00007ffff52bc941 in *__GI___assert_fail (
    assertion=0x7ffff27ae746 "(*get_trx(session)) != __null",
    file=<value optimized out>, line=620,
    function=0x7ffff27b0f00 "virtual drizzled::THR_LOCK_DATA** EmbeddedInnoDBCursor::store_lock(drizzled::Session*, drizzled::THR_LOCK_DATA**, drizzled::thr_lock_type)") at assert.c:81
#3 0x00007ffff278db11 in EmbeddedInnoDBCursor::store_lock (this=0x183e1b0,
    session=0x1836f20, to=0x183edc8,
    lock_type=drizzled::TL_WRITE_CONCURRENT_INSERT)
    at plugin/embedded_innodb/embedded_innodb_engine.cc:620
#4 0x00000000007075c5 in get_lock_data (session=0x1836f20,
    table_ptr=0x183c7c0, count=1, should_lock=true,
    write_lock_used=0x7fffdef91728) at drizzled/lock.cc:631
#5 0x000000000070661f in drizzled::mysql_lock_tables (session=0x1836f20,
    tables=0x183c7c0, count=1, flags=4, need_reopen=0x7fffdef917ef)
    at drizzled/lock.cc:193
#6 0x000000000079d342 in drizzled::Session::lock_tables (this=0x1836f20,
    tables=0x183c228, count=1, need_reopen=0x7fffdef917ef)
    at drizzled/sql_base.cc:2307
#7 0x000000000078355c in drizzled::Session::openTablesLock (this=0x1836f20,
---Type <return> to continue, or q <return> to quit---
    tables=0x183c228) at drizzled/session.cc:1889
#8 0x00000000007aafc7 in drizzled::mysql_insert (session=0x1836f20,
    table_list=0x183c228, fields=..., values_list=..., update_fields=...,
    update_values=..., duplic=drizzled::DUP_ERROR, ignore=false)
    at drizzled/sql_insert.cc:258
#9 0x000000000080ad65 in drizzled::statement::Insert::execute (this=0x1851e30)
    at drizzled/statement/insert.cc:57
#10 0x00000000007bc762 in mysql_execute_command (session=0x1836f20)
    at drizzled/sql_parse.cc:479
#11 0x00000000007bd524 in drizzled::mysql_parse (session=0x1836f20,
    inBuf=0x18327b8 "INSERT INTO t1 VALUES ('40004712','000001','0010',9)",
    length=52) at drizzled/sql_parse.cc:750
#12 0x00000000007bc0b6 in drizzled::dispatch_command (
    command=drizzled::COM_QUERY, session=0x1836f20,
    packet=0x1832f11 "INSERT INTO t1 VALUES ('40004712','000001','0010',9)",
    packet_length=52) at drizzled/sql_parse.cc:224
#13 0x000000000077e82d in ...

[David Shrewsbury (dshrews)]

Don't believe this was meant to be assigned to me.